●  Green

Stage 1: Prime Performance Period (0–1 Year)

Optimal Performance. The device is operating at its best, with excellent sensor accuracy and operational stability. Battery health remains close to its initial level.

●  Blue

Stage 2: Stable Service Period (1–3 Years)

Stable Operation. The device remains in good overall condition and continues to operate reliably. To maintain measurement accuracy, regular cleaning, inspection, and maintenance are recommended according to the maintenance schedule.

●  Orange

Stage 3: Aging Warning Period (3–5 Years)

Performance Degradation. As the device ages, its sensors may experience measurement drift. More frequent inspections and regular calibration are recommended. Battery performance may also gradually decline, increasing the risk of communication interruptions under extremely low-temperature conditions.

●  Red

Stage 4: Extended Service Period (Over 5 Years)

Critical Aging. The device has exceeded its recommended service life. The performance and reliability of key components may have deteriorated significantly, increasing the risk of operational abnormalities or unexpected failure. Continued use in mission-critical applications is not recommended. A comprehensive inspection should be performed promptly, followed by a repair or replacement plan.